Here's an uber short definition for how I think about these terms (concurring with many of the previous respondents): - Social network: ties between people, regardless of mediating infrastructure [think what sociologists study] - Online social network: ties between people that exist within or are created because of online technologies - Social networking: the practice of building one's social network, regardless of mediating infrastructure [think what business professionals are interested in] - Online social networking: the practicing of building one's social network using online technologies - Social network site: websites that support the articulation, display, and utilization of social networks [see "Social Network Sites: Definition, History, and Scholarship for a proper definition] - Social networking site: websites that center on the practice of social networking, whether for business or pleasure [many communities of interest, business networking, and online dating sites fit into this category] In our JCMC special issue, Nicole and I explicitly wanted to pull out the category of new sites exemplified by Facebook, MySpace, etc. While they are a subset of online communities, they are both structurally different than many of them and engender very different practices. We wanted to use nomenclature that captured those differences. Of course, plenty of folks continue to talk about them as social networkING sites and academics, journalists, and marketers frequently clump online dating sites and community sites into this new glittery genre, but we were trying to explicitly avoid this. There is no doubt that a whole lot of sites out there support networking, but that's not what we were trying to highlight when we put together the JCMC special issue. What this means is that I would call Facebook a social network site. I would call Match.com a social networking site. And I would call LinkedIn both a social network site and a social networking site (depending on whether I was talking about the structure or the practice). I would talk about all of them as CMC and social media. I would say that all of them support online social networks (and social networks more broadly). At the end of the day, the big thing to me that makes a social network site a social network site is the articulation, display, and utilization of one's social network. This requires a profile, but a profile alone does not make a social network site. As for sites vs. services... Originally, I was conceiving of sites to be those website-only environments and services to be a broader category that would include mobile apps, downloadable apps, etc. But these lines are increasingly blurry. Now that both FB and MS have mobile apps and most mobile apps have a website as well, it's hard to distinguish the two categories. So I'm a big agnostic about this. My inclination these days is to call them all sites to highlight the digitally mediated component of it (cuz services don't have the same digital ring as sites), but I can be totally convinced otherwise. Anyhow, I hope that helps. I am totally welcome to critiques on how I'm thinking about it but, in my head at least, there's some coherence to these different categories. danah ------ "taken out of context, i must seem so strange" -- ani http://www.zephoria.org/thoughts/ http://www.danah.org/ @zephoria